1 /*
2 * Copyright (c) 2018, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "cds/aotArtifactFinder.hpp"
26 #include "cds/aotCacheAccess.hpp"
27 #include "cds/aotClassInitializer.hpp"
28 #include "cds/aotClassLocation.hpp"
29 #include "cds/aotConstantPoolResolver.hpp"
30 #include "cds/aotLogging.hpp"
31 #include "cds/aotMetaspace.hpp"
32 #include "cds/aotOopChecker.hpp"
33 #include "cds/aotReferenceObjSupport.hpp"
34 #include "cds/archiveBuilder.hpp"
35 #include "cds/archiveHeapLoader.hpp"
36 #include "cds/archiveHeapWriter.hpp"
37 #include "cds/archiveUtils.hpp"
38 #include "cds/cdsConfig.hpp"
39 #include "cds/cdsEnumKlass.hpp"
40 #include "cds/cdsHeapVerifier.hpp"
41 #include "cds/heapShared.hpp"
42 #include "cds/regeneratedClasses.hpp"
43 #include "classfile/classLoaderData.hpp"
44 #include "classfile/javaClasses.inline.hpp"
45 #include "classfile/modules.hpp"
46 #include "classfile/stringTable.hpp"
47 #include "classfile/symbolTable.hpp"
48 #include "classfile/systemDictionary.hpp"
49 #include "classfile/systemDictionaryShared.hpp"
50 #include "classfile/vmClasses.hpp"
51 #include "classfile/vmSymbols.hpp"
52 #include "gc/shared/collectedHeap.hpp"
53 #include "gc/shared/gcLocker.hpp"
54 #include "gc/shared/gcVMOperations.hpp"
55 #include "logging/log.hpp"
56 #include "logging/logStream.hpp"
57 #include "memory/iterator.inline.hpp"
58 #include "memory/resourceArea.hpp"
59 #include "memory/universe.hpp"
60 #include "oops/compressedOops.inline.hpp"
61 #include "oops/fieldStreams.inline.hpp"
62 #include "oops/objArrayOop.inline.hpp"
63 #include "oops/oop.inline.hpp"
64 #include "oops/oopHandle.inline.hpp"
65 #include "oops/typeArrayOop.inline.hpp"
66 #include "prims/jvmtiExport.hpp"
67 #include "runtime/arguments.hpp"
68 #include "runtime/fieldDescriptor.inline.hpp"
69 #include "runtime/init.hpp"
70 #include "runtime/javaCalls.hpp"
71 #include "runtime/mutexLocker.hpp"
72 #include "runtime/safepointVerifiers.hpp"
73 #include "utilities/bitMap.inline.hpp"
74 #include "utilities/copy.hpp"
75 #if INCLUDE_G1GC
76 #include "gc/g1/g1CollectedHeap.hpp"
77 #endif
78
79 #if INCLUDE_CDS_JAVA_HEAP
80
81 struct ArchivableStaticFieldInfo {
82 const char* klass_name;
83 const char* field_name;
84 InstanceKlass* klass;
85 int offset;
86 BasicType type;
87
88 ArchivableStaticFieldInfo(const char* k, const char* f)
89 : klass_name(k), field_name(f), klass(nullptr), offset(0), type(T_ILLEGAL) {}
90
91 bool valid() {
92 return klass_name != nullptr;
93 }
94 };
95
96 class HeapShared::ContextMark : public StackObj {
97 ResourceMark rm;
98 public:
99 ContextMark(const char* c) : rm{} {
100 _context->push(c);
101 }
102 ~ContextMark() {
103 _context->pop();
104 }
105 };
106
107 DumpedInternedStrings *HeapShared::_dumped_interned_strings = nullptr;
108
109 size_t HeapShared::_alloc_count[HeapShared::ALLOC_STAT_SLOTS];
110 size_t HeapShared::_alloc_size[HeapShared::ALLOC_STAT_SLOTS];
111 size_t HeapShared::_total_obj_count;
112 size_t HeapShared::_total_obj_size;
113
114 #ifndef PRODUCT
115 #define ARCHIVE_TEST_FIELD_NAME "archivedObjects"
116 static Array<char>* _archived_ArchiveHeapTestClass = nullptr;
117 static const char* _test_class_name = nullptr;
118 static Klass* _test_class = nullptr;
119 static const ArchivedKlassSubGraphInfoRecord* _test_class_record = nullptr;
120 #endif
121
122
123 //
124 // If you add new entries to the following tables, you should know what you're doing!
125 //
126
127 static ArchivableStaticFieldInfo archive_subgraph_entry_fields[] = {
128 {"java/lang/Integer$IntegerCache", "archivedCache"},
129 {"java/lang/Long$LongCache", "archivedCache"},
130 {"java/lang/Byte$ByteCache", "archivedCache"},
131 {"java/lang/Short$ShortCache", "archivedCache"},
132 {"java/lang/Character$CharacterCache", "archivedCache"},
133 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"},
134 {"sun/util/locale/BaseLocale", "constantBaseLocales"},
135 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"},
136 {"java/util/ImmutableCollections", "archivedObjects"},
137 {"java/lang/ModuleLayer", "EMPTY_LAYER"},
138 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"},
139 {"jdk/internal/math/FDBigInteger", "archivedCaches"},
140 {"java/lang/reflect/Proxy$ProxyBuilder", "archivedData"}, // FIXME -- requires AOTClassLinking
141
142 #ifndef PRODUCT
143 {nullptr, nullptr}, // Extra slot for -XX:ArchiveHeapTestClass
144 #endif
145 {nullptr, nullptr},
146 };
147
148 // full module graph
149 static ArchivableStaticFieldInfo fmg_archive_subgraph_entry_fields[] = {
150 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"},
151 {ARCHIVED_BOOT_LAYER_CLASS, ARCHIVED_BOOT_LAYER_FIELD},
152 {"java/lang/Module$ArchivedData", "archivedData"},
153 {nullptr, nullptr},
154 };
155
156 KlassSubGraphInfo* HeapShared::_dump_time_special_subgraph;
157 ArchivedKlassSubGraphInfoRecord* HeapShared::_run_time_special_subgraph;
158 GrowableArrayCHeap<OopHandle, mtClassShared>* HeapShared::_pending_roots = nullptr;
159 GrowableArrayCHeap<const char*, mtClassShared>* HeapShared::_context = nullptr;
160 GrowableArrayCHeap<OopHandle, mtClassShared>* HeapShared::_root_segments = nullptr;
161 int HeapShared::_root_segment_max_size_elems;
162 OopHandle HeapShared::_scratch_basic_type_mirrors[T_VOID+1];
163 MetaspaceObjToOopHandleTable* HeapShared::_scratch_objects_table = nullptr;
164
165 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], InstanceKlass* ik) {
166 for (int i = 0; fields[i].valid(); i++) {
167 if (fields[i].klass == ik) {
168 return true;
169 }
170 }
171 return false;
172 }
173
174 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) {
175 return is_subgraph_root_class_of(archive_subgraph_entry_fields, ik) ||
176 is_subgraph_root_class_of(fmg_archive_subgraph_entry_fields, ik);
177 }
178
179 oop HeapShared::CachedOopInfo::orig_referrer() const {
180 return _orig_referrer.resolve();
181 }
182
183 unsigned HeapShared::oop_hash(oop const& p) {
184 assert(SafepointSynchronize::is_at_safepoint() ||
185 JavaThread::current()->is_in_no_safepoint_scope(), "sanity");
186 // Do not call p->identity_hash() as that will update the
187 // object header.
188 return primitive_hash(cast_from_oop<intptr_t>(p));
189 }
190
191 unsigned int HeapShared::oop_handle_hash_raw(const OopHandle& oh) {
192 return oop_hash(oh.resolve());
193 }
194
195 unsigned int HeapShared::oop_handle_hash(const OopHandle& oh) {
196 oop o = oh.resolve();
197 if (o == nullptr) {
198 return 0;
199 } else {
200 return o->identity_hash();
201 }
202 }
203
204 bool HeapShared::oop_handle_equals(const OopHandle& a, const OopHandle& b) {
205 return a.resolve() == b.resolve();
206 }
207
208 static void reset_states(oop obj, TRAPS) {
209 Handle h_obj(THREAD, obj);
210 InstanceKlass* klass = InstanceKlass::cast(obj->klass());
211 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
212 Symbol* method_sig = vmSymbols::void_method_signature();
213
214 while (klass != nullptr) {
215 Method* method = klass->find_method(method_name, method_sig);
216 if (method != nullptr) {
217 assert(method->is_private(), "must be");
218 if (log_is_enabled(Debug, aot)) {
219 ResourceMark rm(THREAD);
220 log_debug(aot)(" calling %s", method->name_and_sig_as_C_string());
221 }
222 JavaValue result(T_VOID);
223 JavaCalls::call_special(&result, h_obj, klass,
224 method_name, method_sig, CHECK);
225 }
226 klass = klass->super();
227 }
228 }
229
230 void HeapShared::reset_archived_object_states(TRAPS) {
231 assert(CDSConfig::is_dumping_heap(), "dump-time only");
232 log_debug(aot)("Resetting platform loader");
233 reset_states(SystemDictionary::java_platform_loader(), CHECK);
234 log_debug(aot)("Resetting system loader");
235 reset_states(SystemDictionary::java_system_loader(), CHECK);
236
237 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not
238 // directly used for class loading, but rather is used by the core library
239 // to keep track of resources, etc, loaded by the null class loader.
240 //
241 // Note, this object is non-null, and is not the same as
242 // ClassLoaderData::the_null_class_loader_data()->class_loader(),
243 // which is null.
244 log_debug(aot)("Resetting boot loader");
245 JavaValue result(T_OBJECT);
246 JavaCalls::call_static(&result,
247 vmClasses::jdk_internal_loader_ClassLoaders_klass(),
248 vmSymbols::bootLoader_name(),
249 vmSymbols::void_BuiltinClassLoader_signature(),
250 CHECK);
251 Handle boot_loader(THREAD, result.get_oop());
252 reset_states(boot_loader(), CHECK);
253 }
254
255 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = nullptr;
256
257 bool HeapShared::has_been_archived(oop obj) {
258 assert(CDSConfig::is_dumping_heap(), "dump-time only");
259 OopHandle oh(&obj);
260 return archived_object_cache()->get(oh) != nullptr;
261 }
262
263 int HeapShared::append_root(oop obj) {
264 assert(CDSConfig::is_dumping_heap(), "dump-time only");
265 if (obj != nullptr) {
266 assert(has_been_archived(obj), "must be");
267 }
268 // No GC should happen since we aren't scanning _pending_roots.
269 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
270
271 OopHandle oh(Universe::vm_global(), obj);
272 return _pending_roots->append(oh);
273 }
274
275 objArrayOop HeapShared::root_segment(int segment_idx) {
276 if (CDSConfig::is_dumping_heap() && !CDSConfig::is_dumping_final_static_archive()) {
277 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
278 } else {
279 assert(CDSConfig::is_using_archive(), "must be");
280 }
281
282 objArrayOop segment = (objArrayOop)_root_segments->at(segment_idx).resolve();
283 assert(segment != nullptr, "should have been initialized");
284 return segment;
285 }
286
287 class OrigToScratchObjectTable: public HashTable<OopHandle, OopHandle,
288 36137, // prime number
289 AnyObj::C_HEAP,
290 mtClassShared,
291 HeapShared::oop_handle_hash,
292 HeapShared::oop_handle_equals> {};
293
294 static OrigToScratchObjectTable* _orig_to_scratch_object_table = nullptr;
295
296 void HeapShared::track_scratch_object(oop orig_obj, oop scratch_obj) {
297 MutexLocker ml(ArchivedObjectTables_lock, Mutex::_no_safepoint_check_flag);
298 if (_orig_to_scratch_object_table == nullptr) {
299 _orig_to_scratch_object_table = new (mtClass)OrigToScratchObjectTable();
300 }
301
302 OopHandle orig_h(Universe::vm_global(), orig_obj);
303 OopHandle scratch_h(Universe::vm_global(), scratch_obj);
304 _orig_to_scratch_object_table->put_when_absent(orig_h, scratch_h);
305 }
306
307 oop HeapShared::orig_to_scratch_object(oop orig_obj) {
308 MutexLocker ml(ArchivedObjectTables_lock, Mutex::_no_safepoint_check_flag);
309 if (_orig_to_scratch_object_table != nullptr) {
310 OopHandle orig(&orig_obj);
311 OopHandle* v = _orig_to_scratch_object_table->get(orig);
312 if (v != nullptr) {
313 return v->resolve();
314 }
315 }
316 return nullptr;
317 }
318
319 // Permanent oops are used to support AOT-compiled methods, which may have in-line references
320 // to Strings and MH oops.
321 //
322 // At runtime, these oops are stored in _runtime_permanent_oops (which keeps them alive forever)
323 // and are accssed vis AOTCacheAccess::get_archived_object(int).
324 struct PermanentOopInfo {
325 int _index; // Gets assigned only if HeapShared::get_archived_object_permanent_index() has been called on the object
326 int _heap_offset; // Offset of the object from the bottom of the archived heap.
327 PermanentOopInfo(int index, int heap_offset) : _index(index), _heap_offset(heap_offset) {}
328 };
329
330 class PermanentOopTable: public HashTable<OopHandle, PermanentOopInfo,
331 36137, // prime number
332 AnyObj::C_HEAP,
333 mtClassShared,
334 HeapShared::oop_handle_hash,
335 HeapShared::oop_handle_equals> {};
336
337 static int _dumptime_permanent_oop_count = 0;
338 static PermanentOopTable* _dumptime_permanent_oop_table = nullptr;
339 static GrowableArrayCHeap<OopHandle, mtClassShared>* _runtime_permanent_oops = nullptr;
340
341 // ArchiveHeapWriter adds each archived heap object to _dumptime_permanent_oop_table,
342 // so we can remember their offset (from the bottom of the archived heap).
343 void HeapShared::add_to_permanent_oop_table(oop obj, int offset) {
344 assert_at_safepoint();
345 if (_dumptime_permanent_oop_table == nullptr) {
346 _dumptime_permanent_oop_table = new (mtClass)PermanentOopTable();
347 }
348
349 PermanentOopInfo info(-1, offset);
350 OopHandle oh(Universe::vm_global(), obj);
351 _dumptime_permanent_oop_table->put_when_absent(oh, info);
352 }
353
354 // A permanent index is assigned to an archived object ONLY when
355 // the AOT compiler calls this function.
356 int HeapShared::get_archived_object_permanent_index(oop obj) {
357 MutexLocker ml(ArchivedObjectTables_lock, Mutex::_no_safepoint_check_flag);
358
359 if (!CDSConfig::is_dumping_heap()) {
360 return -1; // Called by the Leyden old workflow
361 }
362 if (_dumptime_permanent_oop_table == nullptr) {
363 return -1;
364 }
365
366 if (_orig_to_scratch_object_table != nullptr) {
367 OopHandle orig(&obj);
368 OopHandle* v = _orig_to_scratch_object_table->get(orig);
369 if (v != nullptr) {
370 obj = v->resolve();
371 }
372 }
373
374 OopHandle tmp(&obj);
375 PermanentOopInfo* info = _dumptime_permanent_oop_table->get(tmp);
376 if (info == nullptr) {
377 return -1;
378 } else {
379 if (info->_index < 0) {
380 info->_index = _dumptime_permanent_oop_count++;
381 }
382 return info->_index;
383 }
384 }
385
386 oop HeapShared::get_archived_object(int permanent_index) {
387 assert(permanent_index >= 0, "sanity");
388 assert(ArchiveHeapLoader::is_in_use(), "sanity");
389 assert(_runtime_permanent_oops != nullptr, "sanity");
390
391 return _runtime_permanent_oops->at(permanent_index).resolve();
392 }
393
394 // Remember all archived heap objects that have a permanent index.
395 // table[i] = offset of oop whose permanent index is i.
396 void CachedCodeDirectoryInternal::dumptime_init_internal() {
397 const int count = _dumptime_permanent_oop_count;
398 if (count == 0) {
399 // Avoid confusing CDS code with zero-sized tables, just return.
400 log_info(cds)("No permanent oops");
401 _permanent_oop_count = count;
402 _permanent_oop_offsets = nullptr;
403 return;
404 }
405
406 int* table = (int*)AOTCacheAccess::allocate_aot_code_region(count * sizeof(int));
407 for (int i = 0; i < count; i++) {
408 table[count] = -1;
409 }
410 _dumptime_permanent_oop_table->iterate([&](OopHandle o, PermanentOopInfo& info) {
411 int index = info._index;
412 if (index >= 0) {
413 assert(index < count, "sanity");
414 table[index] = info._heap_offset;
415 }
416 return true; // continue
417 });
418
419 for (int i = 0; i < count; i++) {
420 assert(table[i] >= 0, "must be");
421 }
422
423 log_info(cds)("Dumped %d permanent oops", count);
424
425 _permanent_oop_count = count;
426 AOTCacheAccess::set_pointer(&_permanent_oop_offsets, table);
427 }
428
429 // This is called during the bootstrap of the production run, before any GC can happen.
430 // Record each permanent oop in a OopHandle for GC safety.
431 void CachedCodeDirectoryInternal::runtime_init_internal() {
432 int count = _permanent_oop_count;
433 int* table = _permanent_oop_offsets;
434 _runtime_permanent_oops = new GrowableArrayCHeap<OopHandle, mtClassShared>();
435 for (int i = 0; i < count; i++) {
436 oop obj = ArchiveHeapLoader::oop_from_offset(table[i]);
437 OopHandle oh(Universe::vm_global(), obj);
438 _runtime_permanent_oops->append(oh);
439 }
440 };
441
442 void HeapShared::get_segment_indexes(int idx, int& seg_idx, int& int_idx) {
443 assert(_root_segment_max_size_elems > 0, "sanity");
444
445 // Try to avoid divisions for the common case.
446 if (idx < _root_segment_max_size_elems) {
447 seg_idx = 0;
448 int_idx = idx;
449 } else {
450 seg_idx = idx / _root_segment_max_size_elems;
451 int_idx = idx % _root_segment_max_size_elems;
452 }
453
454 assert(idx == seg_idx * _root_segment_max_size_elems + int_idx,
455 "sanity: %d index maps to %d segment and %d internal", idx, seg_idx, int_idx);
456 }
457
458 // Returns an objArray that contains all the roots of the archived objects
459 oop HeapShared::get_root(int index, bool clear) {
460 assert(index >= 0, "sanity");
461 assert(!CDSConfig::is_dumping_heap() && CDSConfig::is_using_archive(), "runtime only");
462 assert(!_root_segments->is_empty(), "must have loaded shared heap");
463 int seg_idx, int_idx;
464 get_segment_indexes(index, seg_idx, int_idx);
465 oop result = root_segment(seg_idx)->obj_at(int_idx);
466 if (clear) {
467 clear_root(index);
468 }
469 return result;
470 }
471
472 void HeapShared::clear_root(int index) {
473 assert(index >= 0, "sanity");
474 assert(CDSConfig::is_using_archive(), "must be");
475 if (ArchiveHeapLoader::is_in_use()) {
476 int seg_idx, int_idx;
477 get_segment_indexes(index, seg_idx, int_idx);
478 if (log_is_enabled(Debug, aot, heap)) {
479 oop old = root_segment(seg_idx)->obj_at(int_idx);
480 log_debug(aot, heap)("Clearing root %d: was " PTR_FORMAT, index, p2i(old));
481 }
482 root_segment(seg_idx)->obj_at_put(int_idx, nullptr);
483 }
484 }
485
486 bool HeapShared::archive_object(oop obj, oop referrer, KlassSubGraphInfo* subgraph_info) {
487 assert(CDSConfig::is_dumping_heap(), "dump-time only");
488
489 assert(!obj->is_stackChunk(), "do not archive stack chunks");
490 if (has_been_archived(obj)) {
491 return true;
492 }
493
494 if (ArchiveHeapWriter::is_too_large_to_archive(obj->size())) {
495 log_debug(aot, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: %zu",
496 p2i(obj), obj->size());
497 debug_trace();
498 return false;
499 } else {
500 AOTOopChecker::check(obj); // Make sure contents of this oop are safe.
501
502 count_allocation(obj->size());
503 ArchiveHeapWriter::add_source_obj(obj);
504 CachedOopInfo info = make_cached_oop_info(obj, referrer);
505
506 OopHandle oh(Universe::vm_global(), obj);
507 archived_object_cache()->put_when_absent(oh, info);
508 archived_object_cache()->maybe_grow();
509 mark_native_pointers(obj);
510
511 Klass* k = obj->klass();
512 if (k->is_instance_klass()) {
513 // Whenever we see a non-array Java object of type X, we mark X to be aot-initialized.
514 // This ensures that during the production run, whenever Java code sees a cached object
515 // of type X, we know that X is already initialized. (see TODO comment below ...)
516
517 if (InstanceKlass::cast(k)->is_enum_subclass()
518 // We can't rerun <clinit> of enum classes (see cdsEnumKlass.cpp) so
519 // we must store them as AOT-initialized.
520 || (subgraph_info == _dump_time_special_subgraph))
521 // TODO: we do this only for the special subgraph for now. Extending this to
522 // other subgraphs would require more refactoring of the core library (such as
523 // move some initialization logic into runtimeSetup()).
524 //
525 // For the other subgraphs, we have a weaker mechanism to ensure that
526 // all classes in a subgraph are initialized before the subgraph is programmatically
527 // returned from jdk.internal.misc.CDS::initializeFromArchive().
528 // See HeapShared::initialize_from_archived_subgraph().
529 {
530 AOTArtifactFinder::add_aot_inited_class(InstanceKlass::cast(k));
531 }
532
533 if (java_lang_Class::is_instance(obj)) {
534 Klass* mirror_k = java_lang_Class::as_Klass(obj);
535 if (mirror_k != nullptr) {
536 AOTArtifactFinder::add_cached_class(mirror_k);
537 }
538 } else if (java_lang_invoke_ResolvedMethodName::is_instance(obj)) {
539 Method* m = java_lang_invoke_ResolvedMethodName::vmtarget(obj);
540 if (m != nullptr) {
541 if (RegeneratedClasses::has_been_regenerated(m)) {
542 m = RegeneratedClasses::get_regenerated_object(m);
543 }
544 InstanceKlass* method_holder = m->method_holder();
545 AOTArtifactFinder::add_cached_class(method_holder);
546 }
547 }
548 }
549
550 if (log_is_enabled(Debug, aot, heap)) {
551 ResourceMark rm;
552 LogTarget(Debug, aot, heap) log;
553 LogStream out(log);
554 out.print("Archived heap object " PTR_FORMAT " : %s ",
555 p2i(obj), obj->klass()->external_name());
556 if (java_lang_Class::is_instance(obj)) {
557 Klass* k = java_lang_Class::as_Klass(obj);
558 if (k != nullptr) {
559 out.print("%s", k->external_name());
560 } else {
561 out.print("primitive");
562 }
563 }
564 out.cr();
565 }
566
567 return true;
568 }
569 }
570
571 class MetaspaceObjToOopHandleTable: public HashTable<MetaspaceObj*, OopHandle,
572 36137, // prime number
573 AnyObj::C_HEAP,
574 mtClassShared> {
575 public:
576 oop get_oop(MetaspaceObj* ptr) {
577 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
578 OopHandle* handle = get(ptr);
579 if (handle != nullptr) {
580 return handle->resolve();
581 } else {
582 return nullptr;
583 }
584 }
585 void set_oop(MetaspaceObj* ptr, oop o) {
586 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
587 OopHandle handle(Universe::vm_global(), o);
588 bool is_new = put(ptr, handle);
589 assert(is_new, "cannot set twice");
590 }
591 void remove_oop(MetaspaceObj* ptr) {
592 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
593 OopHandle* handle = get(ptr);
594 if (handle != nullptr) {
595 handle->release(Universe::vm_global());
596 remove(ptr);
597 }
598 }
599 };
600
601 void HeapShared::add_scratch_resolved_references(ConstantPool* src, objArrayOop dest) {
602 if (SystemDictionaryShared::is_builtin_loader(src->pool_holder()->class_loader_data())) {
603 _scratch_objects_table->set_oop(src, dest);
604 }
605 }
606
607 objArrayOop HeapShared::scratch_resolved_references(ConstantPool* src) {
608 return (objArrayOop)_scratch_objects_table->get_oop(src);
609 }
610
611 void HeapShared::init_dumping() {
612 _scratch_objects_table = new (mtClass)MetaspaceObjToOopHandleTable();
613 _pending_roots = new GrowableArrayCHeap<OopHandle, mtClassShared>(500);
614 }
615
616 void HeapShared::init_scratch_objects_for_basic_type_mirrors(TRAPS) {
617 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
618 BasicType bt = (BasicType)i;
619 if (!is_reference_type(bt)) {
620 oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, CHECK);
621 _scratch_basic_type_mirrors[i] = OopHandle(Universe::vm_global(), m);
622 track_scratch_object(Universe::java_mirror(bt), m);
623 }
624 }
625 }
626
627 // Given java_mirror that represents a (primitive or reference) type T,
628 // return the "scratch" version that represents the same type T.
629 // Note that if java_mirror will be returned if it's already a
630 // scratch mirror.
631 //
632 // See java_lang_Class::create_scratch_mirror() for more info.
633 oop HeapShared::scratch_java_mirror(oop java_mirror) {
634 assert(java_lang_Class::is_instance(java_mirror), "must be");
635
636 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
637 BasicType bt = (BasicType)i;
638 if (!is_reference_type(bt)) {
639 if (_scratch_basic_type_mirrors[i].resolve() == java_mirror) {
640 return java_mirror;
641 }
642 }
643 }
644
645 if (java_lang_Class::is_primitive(java_mirror)) {
646 return scratch_java_mirror(java_lang_Class::as_BasicType(java_mirror));
647 } else {
648 return scratch_java_mirror(java_lang_Class::as_Klass(java_mirror));
649 }
650 }
651
652 oop HeapShared::scratch_java_mirror(BasicType t) {
653 assert((uint)t < T_VOID+1, "range check");
654 assert(!is_reference_type(t), "sanity");
655 return _scratch_basic_type_mirrors[t].resolve();
656 }
657
658 oop HeapShared::scratch_java_mirror(Klass* k) {
659 return _scratch_objects_table->get_oop(k);
660 }
661
662 void HeapShared::set_scratch_java_mirror(Klass* k, oop mirror) {
663 track_scratch_object(k->java_mirror(), mirror);
664 _scratch_objects_table->set_oop(k, mirror);
665 }
666
667 void HeapShared::remove_scratch_objects(Klass* k) {
668 // Klass is being deallocated. Java mirror can still be alive, and it should not
669 // point to dead klass. We need to break the link from mirror to the Klass.
670 // See how InstanceKlass::deallocate_contents does it for normal mirrors.
671 oop mirror = _scratch_objects_table->get_oop(k);
672 if (mirror != nullptr) {
673 java_lang_Class::set_klass(mirror, nullptr);
674 }
675 _scratch_objects_table->remove_oop(k);
676 if (k->is_instance_klass()) {
677 _scratch_objects_table->remove(InstanceKlass::cast(k)->constants());
678 }
679 if (mirror != nullptr) {
680 OopHandle tmp(&mirror);
681 OopHandle* v = _orig_to_scratch_object_table->get(tmp);
682 if (v != nullptr) {
683 oop scratch_mirror = v->resolve();
684 java_lang_Class::set_klass(scratch_mirror, nullptr);
685 _orig_to_scratch_object_table->remove(tmp);
686 }
687 }
688 }
689
690 //TODO: we eventually want a more direct test for these kinds of things.
691 //For example the JVM could record some bit of context from the creation
692 //of the klass, such as who called the hidden class factory. Using
693 //string compares on names is fragile and will break as soon as somebody
694 //changes the names in the JDK code. See discussion in JDK-8342481 for
695 //related ideas about marking AOT-related classes.
696 bool HeapShared::is_lambda_form_klass(InstanceKlass* ik) {
697 return ik->is_hidden() &&
698 (ik->name()->starts_with("java/lang/invoke/LambdaForm$MH+") ||
699 ik->name()->starts_with("java/lang/invoke/LambdaForm$DMH+") ||
700 ik->name()->starts_with("java/lang/invoke/LambdaForm$BMH+") ||
701 ik->name()->starts_with("java/lang/invoke/LambdaForm$VH+"));
702 }
703
704 bool HeapShared::is_lambda_proxy_klass(InstanceKlass* ik) {
705 return ik->is_hidden() && (ik->name()->index_of_at(0, "$$Lambda+", 9) > 0);
706 }
707
708 bool HeapShared::is_string_concat_klass(InstanceKlass* ik) {
709 return ik->is_hidden() && ik->name()->starts_with("java/lang/String$$StringConcat");
710 }
711
712 bool HeapShared::is_archivable_hidden_klass(InstanceKlass* ik) {
713 return CDSConfig::is_dumping_method_handles() &&
714 (is_lambda_form_klass(ik) || is_lambda_proxy_klass(ik) || is_string_concat_klass(ik));
715 }
716
717
718 void HeapShared::copy_and_rescan_aot_inited_mirror(InstanceKlass* ik) {
719 ik->set_has_aot_initialized_mirror();
720
721 oop orig_mirror;
722 if (RegeneratedClasses::is_regenerated_object(ik)) {
723 InstanceKlass* orig_ik = RegeneratedClasses::get_original_object(ik);
724 precond(orig_ik->is_initialized());
725 orig_mirror = orig_ik->java_mirror();
726 } else {
727 precond(ik->is_initialized());
728 orig_mirror = ik->java_mirror();
729 }
730
731 oop m = scratch_java_mirror(ik);
732 int nfields = 0;
733 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
734 if (fs.access_flags().is_static()) {
735 fieldDescriptor& fd = fs.field_descriptor();
736 int offset = fd.offset();
737 switch (fd.field_type()) {
738 case T_OBJECT:
739 case T_ARRAY:
740 {
741 oop field_obj = orig_mirror->obj_field(offset);
742 m->obj_field_put(offset, field_obj);
743 if (field_obj != nullptr) {
744 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, field_obj);
745 assert(success, "sanity");
746 }
747 }
748 break;
749 case T_BOOLEAN:
750 m->bool_field_put(offset, orig_mirror->bool_field(offset));
751 break;
752 case T_BYTE:
753 m->byte_field_put(offset, orig_mirror->byte_field(offset));
754 break;
755 case T_SHORT:
756 m->short_field_put(offset, orig_mirror->short_field(offset));
757 break;
758 case T_CHAR:
759 m->char_field_put(offset, orig_mirror->char_field(offset));
760 break;
761 case T_INT:
762 m->int_field_put(offset, orig_mirror->int_field(offset));
763 break;
764 case T_LONG:
765 m->long_field_put(offset, orig_mirror->long_field(offset));
766 break;
767 case T_FLOAT:
768 m->float_field_put(offset, orig_mirror->float_field(offset));
769 break;
770 case T_DOUBLE:
771 m->double_field_put(offset, orig_mirror->double_field(offset));
772 break;
773 default:
774 ShouldNotReachHere();
775 }
776 nfields ++;
777 }
778 }
779
780 oop class_data = java_lang_Class::class_data(orig_mirror);
781 java_lang_Class::set_class_data(m, class_data);
782 if (class_data != nullptr) {
783 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, class_data);
784 assert(success, "sanity");
785 }
786
787 if (log_is_enabled(Debug, aot, init)) {
788 ResourceMark rm;
789 log_debug(aot, init)("copied %3d field(s) in aot-initialized mirror %s%s%s", nfields, ik->external_name(),
790 ik->is_hidden() ? " (hidden)" : "",
791 ik->is_enum_subclass() ? " (enum)" : "");
792 }
793 }
794
795 void HeapShared::copy_java_mirror(oop orig_mirror, oop scratch_m) {
796 // We need to retain the identity_hash, because it may have been used by some hashtables
797 // in the shared heap.
798 if (!orig_mirror->fast_no_hash_check()) {
799 intptr_t src_hash = orig_mirror->identity_hash();
800 if (UseCompactObjectHeaders) {
801 narrowKlass nk = CompressedKlassPointers::encode(orig_mirror->klass());
802 scratch_m->set_mark(markWord::prototype().set_narrow_klass(nk).copy_set_hash(src_hash));
803 } else {
804 scratch_m->set_mark(markWord::prototype().copy_set_hash(src_hash));
805 }
806 assert(scratch_m->mark().is_unlocked(), "sanity");
807
808 DEBUG_ONLY(intptr_t archived_hash = scratch_m->identity_hash());
809 assert(src_hash == archived_hash, "Different hash codes: original " INTPTR_FORMAT ", archived " INTPTR_FORMAT, src_hash, archived_hash);
810 }
811
812 if (CDSConfig::is_dumping_aot_linked_classes()) {
813 java_lang_Class::set_module(scratch_m, java_lang_Class::module(orig_mirror));
814 java_lang_Class::set_protection_domain(scratch_m, java_lang_Class::protection_domain(orig_mirror));
815 }
816
817 Klass* k = java_lang_Class::as_Klass(orig_mirror); // is null Universe::void_mirror();
818 if (CDSConfig::is_dumping_reflection_data() &&
819 k != nullptr && k->is_instance_klass() &&
820 java_lang_Class::reflection_data(orig_mirror) != nullptr &&
821 AOTConstantPoolResolver::can_archive_reflection_data(InstanceKlass::cast(k))) {
822 java_lang_Class::set_reflection_data(scratch_m, java_lang_Class::reflection_data(orig_mirror));
823 }
824 }
825
826 static objArrayOop get_archived_resolved_references(InstanceKlass* src_ik) {
827 if (SystemDictionaryShared::is_builtin_loader(src_ik->class_loader_data())) {
828 objArrayOop rr = src_ik->constants()->resolved_references_or_null();
829 if (rr != nullptr && !ArchiveHeapWriter::is_too_large_to_archive(rr)) {
830 return HeapShared::scratch_resolved_references(src_ik->constants());
831 }
832 }
833 return nullptr;
834 }
835
836 void HeapShared::archive_strings() {
837 oop shared_strings_array = StringTable::init_shared_strings_array();
838 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, shared_strings_array);
839 assert(success, "shared strings array must not point to arrays or strings that are too large to archive");
840 StringTable::set_shared_strings_array_index(append_root(shared_strings_array));
841 }
842
843 int HeapShared::archive_exception_instance(oop exception) {
844 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, exception);
845 assert(success, "sanity");
846 return append_root(exception);
847 }
848
849 void HeapShared::mark_native_pointers(oop orig_obj) {
850 if (java_lang_Class::is_instance(orig_obj)) {
851 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::klass_offset());
852 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::array_klass_offset());
853 } else if (java_lang_invoke_ResolvedMethodName::is_instance(orig_obj)) {
854 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_invoke_ResolvedMethodName::vmtarget_offset());
855 }
856 }
857
858 void HeapShared::get_pointer_info(oop src_obj, bool& has_oop_pointers, bool& has_native_pointers) {
859 OopHandle oh(&src_obj);
860 CachedOopInfo* info = archived_object_cache()->get(oh);
861 assert(info != nullptr, "must be");
862 has_oop_pointers = info->has_oop_pointers();
863 has_native_pointers = info->has_native_pointers();
864 }
865
866 void HeapShared::set_has_native_pointers(oop src_obj) {
867 OopHandle oh(&src_obj);
868 CachedOopInfo* info = archived_object_cache()->get(oh);
869 assert(info != nullptr, "must be");
870 info->set_has_native_pointers();
871 }
872
873 // Between start_scanning_for_oops() and end_scanning_for_oops(), we discover all Java heap objects that
874 // should be stored in the AOT cache. The scanning is coordinated by AOTArtifactFinder.
875 void HeapShared::start_scanning_for_oops() {
876 {
877 NoSafepointVerifier nsv;
878
879 // The special subgraph doesn't belong to any class. We use Object_klass() here just
880 // for convenience.
881 _dump_time_special_subgraph = init_subgraph_info(vmClasses::Object_klass(), false);
882 _context = new GrowableArrayCHeap<const char*, mtClassShared>(250);
883
884 // Cache for recording where the archived objects are copied to
885 create_archived_object_cache();
886
887 if (UseCompressedOops || UseG1GC) {
888 aot_log_info(aot)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
889 UseCompressedOops ? p2i(CompressedOops::begin()) :
890 p2i((address)G1CollectedHeap::heap()->reserved().start()),
891 UseCompressedOops ? p2i(CompressedOops::end()) :
892 p2i((address)G1CollectedHeap::heap()->reserved().end()));
893 }
894
895 archive_subgraphs();
896 }
897
898 init_seen_objects_table();
899 Universe::archive_exception_instances();
900 }
901
902 void HeapShared::end_scanning_for_oops() {
903 archive_strings();
904 delete_seen_objects_table();
905 }
906
907 void HeapShared::write_heap(ArchiveHeapInfo *heap_info) {
908 {
909 NoSafepointVerifier nsv;
910 if (!SkipArchiveHeapVerification) {
911 CDSHeapVerifier::verify();
912 }
913 check_special_subgraph_classes();
914 }
915
916 StringTable::write_shared_table();
917 GrowableArrayCHeap<oop, mtClassShared>* roots = new GrowableArrayCHeap<oop, mtClassShared>(_pending_roots->length());
918 for (int i = 0; i < _pending_roots->length(); i++) {
919 roots->append(_pending_roots->at(i).resolve());
920 }
921 ArchiveHeapWriter::write(roots, heap_info);
922 delete roots;
923
924 ArchiveBuilder::OtherROAllocMark mark;
925 write_subgraph_info_table();
926 }
927
928 void HeapShared::scan_java_mirror(oop orig_mirror) {
929 oop m = scratch_java_mirror(orig_mirror);
930 if (m != nullptr) { // nullptr if for custom class loader
931 copy_java_mirror(orig_mirror, m);
932 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, m);
933 assert(success, "sanity");
934
935 oop extra;
936 if ((extra = java_lang_Class::reflection_data(m)) != nullptr) {
937 success = archive_reachable_objects_from(1, _dump_time_special_subgraph, extra);
938 assert(success, "sanity");
939 }
940 }
941 }
942
943 void HeapShared::scan_java_class(Klass* orig_k) {
944 scan_java_mirror(orig_k->java_mirror());
945
946 if (orig_k->is_instance_klass()) {
947 InstanceKlass* orig_ik = InstanceKlass::cast(orig_k);
948 orig_ik->constants()->prepare_resolved_references_for_archiving();
949 objArrayOop rr = get_archived_resolved_references(orig_ik);
950 if (rr != nullptr) {
951 bool success = HeapShared::archive_reachable_objects_from(1, _dump_time_special_subgraph, rr);
952 assert(success, "must be");
953 }
954 }
955 }
956
957 void HeapShared::archive_subgraphs() {
958 assert(CDSConfig::is_dumping_heap(), "must be");
959
960 archive_object_subgraphs(archive_subgraph_entry_fields,
961 false /* is_full_module_graph */);
962
963 if (CDSConfig::is_dumping_full_module_graph()) {
964 archive_object_subgraphs(fmg_archive_subgraph_entry_fields,
965 true /* is_full_module_graph */);
966 Modules::verify_archived_modules();
967 }
968 }
969
970 //
971 // Subgraph archiving support
972 //
973 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr;
974 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
975
976 // Get the subgraph_info for Klass k. A new subgraph_info is created if
977 // there is no existing one for k. The subgraph_info records the "buffered"
978 // address of the class.
979 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
980 assert(CDSConfig::is_dumping_heap(), "dump time only");
981 bool created;
982 KlassSubGraphInfo* info =
983 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(k, is_full_module_graph),
984 &created);
985 assert(created, "must not initialize twice");
986 return info;
987 }
988
989 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
990 assert(CDSConfig::is_dumping_heap(), "dump time only");
991 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
992 assert(info != nullptr, "must have been initialized");
993 return info;
994 }
995
996 // Add an entry field to the current KlassSubGraphInfo.
997 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) {
998 assert(CDSConfig::is_dumping_heap(), "dump time only");
999 if (_subgraph_entry_fields == nullptr) {
1000 _subgraph_entry_fields =
1001 new (mtClass) GrowableArray<int>(10, mtClass);
1002 }
1003 _subgraph_entry_fields->append(static_field_offset);
1004 _subgraph_entry_fields->append(HeapShared::append_root(v));
1005 }
1006
1007 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
1008 // Only objects of boot classes can be included in sub-graph.
1009 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
1010 assert(CDSConfig::is_dumping_heap(), "dump time only");
1011
1012 if (_subgraph_object_klasses == nullptr) {
1013 _subgraph_object_klasses =
1014 new (mtClass) GrowableArray<Klass*>(50, mtClass);
1015 }
1016
1017 if (_k == orig_k) {
1018 // Don't add the Klass containing the sub-graph to it's own klass
1019 // initialization list.
1020 return;
1021 }
1022
1023 if (orig_k->is_instance_klass()) {
1024 #ifdef ASSERT
1025 InstanceKlass* ik = InstanceKlass::cast(orig_k);
1026 if (CDSConfig::is_dumping_method_handles()) {
1027 // -XX:AOTInitTestClass must be used carefully in regression tests to
1028 // include only classes that are safe to aot-initialize.
1029 assert(ik->class_loader() == nullptr ||
1030 HeapShared::is_lambda_proxy_klass(ik) ||
1031 AOTClassInitializer::has_test_class(),
1032 "we can archive only instances of boot classes or lambda proxy classes");
1033 } else {
1034 assert(ik->class_loader() == nullptr, "must be boot class");
1035 }
1036 #endif
1037 // vmClasses::xxx_klass() are not updated, need to check
1038 // the original Klass*
1039 if (orig_k == vmClasses::String_klass() ||
1040 orig_k == vmClasses::Object_klass()) {
1041 // Initialized early during VM initialization. No need to be added
1042 // to the sub-graph object class list.
1043 return;
1044 }
1045 check_allowed_klass(InstanceKlass::cast(orig_k));
1046 } else if (orig_k->is_objArray_klass()) {
1047 Klass* abk = ObjArrayKlass::cast(orig_k)->bottom_klass();
1048 if (abk->is_instance_klass()) {
1049 assert(InstanceKlass::cast(abk)->defined_by_boot_loader(),
1050 "must be boot class");
1051 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass()));
1052 }
1053 if (orig_k == Universe::objectArrayKlass()) {
1054 // Initialized early during Universe::genesis. No need to be added
1055 // to the list.
1056 return;
1057 }
1058 } else {
1059 assert(orig_k->is_typeArray_klass(), "must be");
1060 // Primitive type arrays are created early during Universe::genesis.
1061 return;
1062 }
1063
1064 if (log_is_enabled(Debug, aot, heap)) {
1065 if (!_subgraph_object_klasses->contains(orig_k)) {
1066 ResourceMark rm;
1067 log_debug(aot, heap)("Adding klass %s", orig_k->external_name());
1068 }
1069 }
1070
1071 _subgraph_object_klasses->append_if_missing(orig_k);
1072 _has_non_early_klasses |= is_non_early_klass(orig_k);
1073 }
1074
1075 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) {
1076 #ifndef PRODUCT
1077 if (AOTClassInitializer::has_test_class()) {
1078 // The tests can cache arbitrary types of objects.
1079 return;
1080 }
1081 #endif
1082
1083 if (ik->module()->name() == vmSymbols::java_base()) {
1084 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package");
1085 return;
1086 }
1087
1088 const char* lambda_msg = "";
1089 if (CDSConfig::is_dumping_method_handles()) {
1090 lambda_msg = ", or a lambda proxy class";
1091 if (HeapShared::is_lambda_proxy_klass(ik) &&
1092 (ik->class_loader() == nullptr ||
1093 ik->class_loader() == SystemDictionary::java_platform_loader() ||
1094 ik->class_loader() == SystemDictionary::java_system_loader())) {
1095 return;
1096 }
1097 }
1098
1099 #ifndef PRODUCT
1100 if (!ik->module()->is_named() && ik->package() == nullptr && ArchiveHeapTestClass != nullptr) {
1101 // This class is loaded by ArchiveHeapTestClass
1102 return;
1103 }
1104 const char* testcls_msg = ", or a test class in an unnamed package of an unnamed module";
1105 #else
1106 const char* testcls_msg = "";
1107 #endif
1108
1109 ResourceMark rm;
1110 log_error(aot, heap)("Class %s not allowed in archive heap. Must be in java.base%s%s",
1111 ik->external_name(), lambda_msg, testcls_msg);
1112 AOTMetaspace::unrecoverable_writing_error();
1113 }
1114
1115 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
1116 if (k->is_objArray_klass()) {
1117 k = ObjArrayKlass::cast(k)->bottom_klass();
1118 }
1119 if (k->is_instance_klass()) {
1120 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
1121 ResourceMark rm;
1122 log_info(aot, heap)("non-early: %s", k->external_name());
1123 return true;
1124 } else {
1125 return false;
1126 }
1127 } else {
1128 return false;
1129 }
1130 }
1131
1132 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
1133 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
1134 _k = ArchiveBuilder::get_buffered_klass(info->klass());
1135 _entry_field_records = nullptr;
1136 _subgraph_object_klasses = nullptr;
1137 _is_full_module_graph = info->is_full_module_graph();
1138
1139 if (_is_full_module_graph) {
1140 // Consider all classes referenced by the full module graph as early -- we will be
1141 // allocating objects of these classes during JVMTI early phase, so they cannot
1142 // be processed by (non-early) JVMTI ClassFileLoadHook
1143 _has_non_early_klasses = false;
1144 } else {
1145 _has_non_early_klasses = info->has_non_early_klasses();
1146 }
1147
1148 if (_has_non_early_klasses) {
1149 ResourceMark rm;
1150 log_info(aot, heap)(
1151 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
1152 _k->external_name());
1153 }
1154
1155 // populate the entry fields
1156 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
1157 if (entry_fields != nullptr) {
1158 int num_entry_fields = entry_fields->length();
1159 assert(num_entry_fields % 2 == 0, "sanity");
1160 _entry_field_records =
1161 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
1162 for (int i = 0 ; i < num_entry_fields; i++) {
1163 _entry_field_records->at_put(i, entry_fields->at(i));
1164 }
1165 }
1166
1167 // <recorded_klasses> has the Klasses of all the objects that are referenced by this subgraph.
1168 // Copy those that need to be explicitly initialized into <_subgraph_object_klasses>.
1169 GrowableArray<Klass*>* recorded_klasses = info->subgraph_object_klasses();
1170 if (recorded_klasses != nullptr) {
1171 // AOT-inited classes are automatically marked as "initialized" during bootstrap. When
1172 // programmatically loading a subgraph, we only need to explicitly initialize the classes
1173 // that are not aot-inited.
1174 int num_to_copy = 0;
1175 for (int i = 0; i < recorded_klasses->length(); i++) {
1176 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1177 if (!subgraph_k->has_aot_initialized_mirror()) {
1178 num_to_copy ++;
1179 }
1180 }
1181
1182 _subgraph_object_klasses = ArchiveBuilder::new_ro_array<Klass*>(num_to_copy);
1183 bool is_special = (_k == ArchiveBuilder::get_buffered_klass(vmClasses::Object_klass()));
1184 for (int i = 0, n = 0; i < recorded_klasses->length(); i++) {
1185 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1186 if (subgraph_k->has_aot_initialized_mirror()) {
1187 continue;
1188 }
1189 if (log_is_enabled(Info, aot, heap)) {
1190 ResourceMark rm;
1191 const char* owner_name = is_special ? "<special>" : _k->external_name();
1192 if (subgraph_k->is_instance_klass()) {
1193 InstanceKlass* src_ik = InstanceKlass::cast(ArchiveBuilder::current()->get_source_addr(subgraph_k));
1194 }
1195 log_info(aot, heap)(
1196 "Archived object klass %s (%2d) => %s",
1197 owner_name, n, subgraph_k->external_name());
1198 }
1199 _subgraph_object_klasses->at_put(n, subgraph_k);
1200 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(n));
1201 n++;
1202 }
1203 }
1204
1205 ArchivePtrMarker::mark_pointer(&_k);
1206 ArchivePtrMarker::mark_pointer(&_entry_field_records);
1207 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
1208 }
1209
1210 class HeapShared::CopyKlassSubGraphInfoToArchive : StackObj {
1211 CompactHashtableWriter* _writer;
1212 public:
1213 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
1214
1215 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
1216 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) {
1217 ArchivedKlassSubGraphInfoRecord* record = HeapShared::archive_subgraph_info(&info);
1218 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass);
1219 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k);
1220 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record);
1221 _writer->add(hash, delta);
1222 }
1223 return true; // keep on iterating
1224 }
1225 };
1226
1227 ArchivedKlassSubGraphInfoRecord* HeapShared::archive_subgraph_info(KlassSubGraphInfo* info) {
1228 ArchivedKlassSubGraphInfoRecord* record =
1229 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
1230 record->init(info);
1231 if (info == _dump_time_special_subgraph) {
1232 _run_time_special_subgraph = record;
1233 }
1234 return record;
1235 }
1236
1237 // Build the records of archived subgraph infos, which include:
1238 // - Entry points to all subgraphs from the containing class mirror. The entry
1239 // points are static fields in the mirror. For each entry point, the field
1240 // offset, and value are recorded in the sub-graph
1241 // info. The value is stored back to the corresponding field at runtime.
1242 // - A list of klasses that need to be loaded/initialized before archived
1243 // java object sub-graph can be accessed at runtime.
1244 void HeapShared::write_subgraph_info_table() {
1245 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
1246 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
1247 CompactHashtableStats stats;
1248
1249 _run_time_subgraph_info_table.reset();
1250
1251 CompactHashtableWriter writer(d_table->_count, &stats);
1252 CopyKlassSubGraphInfoToArchive copy(&writer);
1253 d_table->iterate(©);
1254 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
1255
1256 #ifndef PRODUCT
1257 if (ArchiveHeapTestClass != nullptr) {
1258 size_t len = strlen(ArchiveHeapTestClass) + 1;
1259 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len);
1260 strncpy(array->adr_at(0), ArchiveHeapTestClass, len);
1261 _archived_ArchiveHeapTestClass = array;
1262 }
1263 #endif
1264 if (log_is_enabled(Info, aot, heap)) {
1265 print_stats();
1266 }
1267 }
1268
1269 void HeapShared::add_root_segment(objArrayOop segment_oop) {
1270 assert(segment_oop != nullptr, "must be");
1271 assert(ArchiveHeapLoader::is_in_use(), "must be");
1272 if (_root_segments == nullptr) {
1273 _root_segments = new GrowableArrayCHeap<OopHandle, mtClassShared>(10);
1274 }
1275 _root_segments->push(OopHandle(Universe::vm_global(), segment_oop));
1276 }
1277
1278 void HeapShared::init_root_segment_sizes(int max_size_elems) {
1279 _root_segment_max_size_elems = max_size_elems;
1280 }
1281
1282 void HeapShared::serialize_tables(SerializeClosure* soc) {
1283
1284 #ifndef PRODUCT
1285 soc->do_ptr(&_archived_ArchiveHeapTestClass);
1286 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) {
1287 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0);
1288 setup_test_class(_test_class_name);
1289 }
1290 #endif
1291
1292 _run_time_subgraph_info_table.serialize_header(soc);
1293 soc->do_ptr(&_run_time_special_subgraph);
1294 }
1295
1296 static void verify_the_heap(Klass* k, const char* which) {
1297 if (VerifyArchivedFields > 0) {
1298 ResourceMark rm;
1299 log_info(aot, heap)("Verify heap %s initializing static field(s) in %s",
1300 which, k->external_name());
1301
1302 VM_Verify verify_op;
1303 VMThread::execute(&verify_op);
1304
1305 if (VerifyArchivedFields > 1 && is_init_completed()) {
1306 // At this time, the oop->klass() of some archived objects in the heap may not
1307 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
1308 // have enough information (object size, oop maps, etc) so that a GC can be safely
1309 // performed.
1310 //
1311 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
1312 // to check for GC safety.
1313 log_info(aot, heap)("Trigger GC %s initializing static field(s) in %s",
1314 which, k->external_name());
1315 FlagSetting fs1(VerifyBeforeGC, true);
1316 FlagSetting fs2(VerifyDuringGC, true);
1317 FlagSetting fs3(VerifyAfterGC, true);
1318 Universe::heap()->collect(GCCause::_java_lang_system_gc);
1319 }
1320 }
1321 }
1322
1323 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
1324 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
1325 //
1326 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
1327 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
1328 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
1329 void HeapShared::resolve_classes(JavaThread* current) {
1330 assert(CDSConfig::is_using_archive(), "runtime only!");
1331 if (!ArchiveHeapLoader::is_in_use()) {
1332 return; // nothing to do
1333 }
1334
1335 if (!CDSConfig::is_using_aot_linked_classes()) {
1336 assert( _run_time_special_subgraph != nullptr, "must be");
1337 Array<Klass*>* klasses = _run_time_special_subgraph->subgraph_object_klasses();
1338 if (klasses != nullptr) {
1339 for (int i = 0; i < klasses->length(); i++) {
1340 Klass* k = klasses->at(i);
1341 ExceptionMark em(current); // no exception can happen here
1342 resolve_or_init(k, /*do_init*/false, current);
1343 }
1344 }
1345 }
1346
1347 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields);
1348 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields);
1349 }
1350
1351 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) {
1352 for (int i = 0; fields[i].valid(); i++) {
1353 ArchivableStaticFieldInfo* info = &fields[i];
1354 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1355 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
1356 assert(k != nullptr && k->defined_by_boot_loader(), "sanity");
1357 resolve_classes_for_subgraph_of(current, k);
1358 }
1359 }
1360
1361 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) {
1362 JavaThread* THREAD = current;
1363 ExceptionMark em(THREAD);
1364 const ArchivedKlassSubGraphInfoRecord* record =
1365 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
1366 if (HAS_PENDING_EXCEPTION) {
1367 CLEAR_PENDING_EXCEPTION;
1368 }
1369 if (record == nullptr) {
1370 clear_archived_roots_of(k);
1371 }
1372 }
1373
1374 void HeapShared::initialize_java_lang_invoke(TRAPS) {
1375 if (CDSConfig::is_using_aot_linked_classes() || CDSConfig::is_dumping_method_handles()) {
1376 resolve_or_init("java/lang/invoke/Invokers$Holder", true, CHECK);
1377 resolve_or_init("java/lang/invoke/MethodHandle", true, CHECK);
1378 resolve_or_init("java/lang/invoke/MethodHandleNatives", true, CHECK);
1379 resolve_or_init("java/lang/invoke/DirectMethodHandle$Holder", true, CHECK);
1380 resolve_or_init("java/lang/invoke/DelegatingMethodHandle$Holder", true, CHECK);
1381 resolve_or_init("java/lang/invoke/LambdaForm$Holder", true, CHECK);
1382 resolve_or_init("java/lang/invoke/BoundMethodHandle$Species_L", true, CHECK);
1383 }
1384 }
1385
1386 // Initialize the InstanceKlasses of objects that are reachable from the following roots:
1387 // - interned strings
1388 // - Klass::java_mirror() -- including aot-initialized mirrors such as those of Enum klasses.
1389 // - ConstantPool::resolved_references()
1390 // - Universe::<xxx>_exception_instance()
1391 //
1392 // For example, if this enum class is initialized at AOT cache assembly time:
1393 //
1394 // enum Fruit {
1395 // APPLE, ORANGE, BANANA;
1396 // static final Set<Fruit> HAVE_SEEDS = new HashSet<>(Arrays.asList(APPLE, ORANGE));
1397 // }
1398 //
1399 // the aot-initialized mirror of Fruit has a static field that references HashSet, which
1400 // should be initialized before any Java code can access the Fruit class. Note that
1401 // HashSet itself doesn't necessary need to be an aot-initialized class.
1402 void HeapShared::init_classes_for_special_subgraph(Handle class_loader, TRAPS) {
1403 if (!ArchiveHeapLoader::is_in_use()) {
1404 return;
1405 }
1406
1407 assert( _run_time_special_subgraph != nullptr, "must be");
1408 Array<Klass*>* klasses = _run_time_special_subgraph->subgraph_object_klasses();
1409 if (klasses != nullptr) {
1410 for (int pass = 0; pass < 2; pass ++) {
1411 for (int i = 0; i < klasses->length(); i++) {
1412 Klass* k = klasses->at(i);
1413 if (k->class_loader_data() == nullptr) {
1414 // This class is not yet loaded. We will initialize it in a later phase.
1415 // For example, we have loaded only AOTLinkedClassCategory::BOOT1 classes
1416 // but k is part of AOTLinkedClassCategory::BOOT2.
1417 continue;
1418 }
1419 if (k->class_loader() == class_loader()) {
1420 if (pass == 0) {
1421 if (k->is_instance_klass()) {
1422 InstanceKlass::cast(k)->link_class(CHECK);
1423 }
1424 } else {
1425 resolve_or_init(k, /*do_init*/true, CHECK);
1426 }
1427 }
1428 }
1429 }
1430 }
1431 }
1432
1433 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) {
1434 JavaThread* THREAD = current;
1435 if (!ArchiveHeapLoader::is_in_use()) {
1436 return; // nothing to do
1437 }
1438
1439 if (k->name()->equals("jdk/internal/module/ArchivedModuleGraph") &&
1440 !CDSConfig::is_using_optimized_module_handling() &&
1441 // archive was created with --module-path
1442 AOTClassLocationConfig::runtime()->num_module_paths() > 0) {
1443 // ArchivedModuleGraph was created with a --module-path that's different than the runtime --module-path.
1444 // Thus, it might contain references to modules that do not exist at runtime. We cannot use it.
1445 log_info(aot, heap)("Skip initializing ArchivedModuleGraph subgraph: is_using_optimized_module_handling=%s num_module_paths=%d",
1446 BOOL_TO_STR(CDSConfig::is_using_optimized_module_handling()),
1447 AOTClassLocationConfig::runtime()->num_module_paths());
1448 return;
1449 }
1450
1451 ExceptionMark em(THREAD);
1452 const ArchivedKlassSubGraphInfoRecord* record =
1453 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
1454
1455 if (HAS_PENDING_EXCEPTION) {
1456 CLEAR_PENDING_EXCEPTION;
1457 // None of the field value will be set if there was an exception when initializing the classes.
1458 // The java code will not see any of the archived objects in the
1459 // subgraphs referenced from k in this case.
1460 return;
1461 }
1462
1463 if (record != nullptr) {
1464 init_archived_fields_for(k, record);
1465 }
1466 }
1467
1468 const ArchivedKlassSubGraphInfoRecord*
1469 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
1470 assert(!CDSConfig::is_dumping_heap(), "Should not be called when dumping heap");
1471
1472 if (!k->in_aot_cache()) {
1473 return nullptr;
1474 }
1475 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1476 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1477
1478 #ifndef PRODUCT
1479 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) {
1480 _test_class = k;
1481 _test_class_record = record;
1482 }
1483 #endif
1484
1485 // Initialize from archived data. Currently this is done only
1486 // during VM initialization time. No lock is needed.
1487 if (record == nullptr) {
1488 if (log_is_enabled(Info, aot, heap)) {
1489 ResourceMark rm(THREAD);
1490 log_info(aot, heap)("subgraph %s is not recorded",
1491 k->external_name());
1492 }
1493 return nullptr;
1494 } else {
1495 if (record->is_full_module_graph() && !CDSConfig::is_using_full_module_graph()) {
1496 if (log_is_enabled(Info, aot, heap)) {
1497 ResourceMark rm(THREAD);
1498 log_info(aot, heap)("subgraph %s cannot be used because full module graph is disabled",
1499 k->external_name());
1500 }
1501 return nullptr;
1502 }
1503
1504 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
1505 if (log_is_enabled(Info, aot, heap)) {
1506 ResourceMark rm(THREAD);
1507 log_info(aot, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
1508 k->external_name());
1509 }
1510 return nullptr;
1511 }
1512
1513 if (log_is_enabled(Info, aot, heap)) {
1514 ResourceMark rm;
1515 log_info(aot, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name());
1516 }
1517
1518 resolve_or_init(k, do_init, CHECK_NULL);
1519
1520 // Load/link/initialize the klasses of the objects in the subgraph.
1521 // nullptr class loader is used.
1522 Array<Klass*>* klasses = record->subgraph_object_klasses();
1523 if (klasses != nullptr) {
1524 for (int i = 0; i < klasses->length(); i++) {
1525 Klass* klass = klasses->at(i);
1526 if (!klass->in_aot_cache()) {
1527 return nullptr;
1528 }
1529 resolve_or_init(klass, do_init, CHECK_NULL);
1530 }
1531 }
1532 }
1533
1534 return record;
1535 }
1536
1537 void HeapShared::resolve_or_init(const char* klass_name, bool do_init, TRAPS) {
1538 TempNewSymbol klass_name_sym = SymbolTable::new_symbol(klass_name);
1539 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name_sym);
1540 if (k == nullptr) {
1541 return;
1542 }
1543 assert(k->defined_by_boot_loader(), "sanity");
1544 resolve_or_init(k, false, CHECK);
1545 if (do_init) {
1546 resolve_or_init(k, true, CHECK);
1547 }
1548 }
1549
1550 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
1551 if (!do_init) {
1552 if (k->class_loader_data() == nullptr) {
1553 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
1554 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
1555 }
1556 } else {
1557 assert(k->class_loader_data() != nullptr, "must have been resolved by HeapShared::resolve_classes");
1558 if (k->is_instance_klass()) {
1559 InstanceKlass* ik = InstanceKlass::cast(k);
1560 ik->initialize(CHECK);
1561 } else if (k->is_objArray_klass()) {
1562 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
1563 oak->initialize(CHECK);
1564 }
1565 }
1566 }
1567
1568 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
1569 verify_the_heap(k, "before");
1570
1571 // Load the subgraph entry fields from the record and store them back to
1572 // the corresponding fields within the mirror.
1573 oop m = k->java_mirror();
1574 Array<int>* entry_field_records = record->entry_field_records();
1575 if (entry_field_records != nullptr) {
1576 int efr_len = entry_field_records->length();
1577 assert(efr_len % 2 == 0, "sanity");
1578 for (int i = 0; i < efr_len; i += 2) {
1579 int field_offset = entry_field_records->at(i);
1580 int root_index = entry_field_records->at(i+1);
1581 oop v = get_root(root_index, /*clear=*/true);
1582 if (k->has_aot_initialized_mirror()) {
1583 assert(v == m->obj_field(field_offset), "must be aot-initialized");
1584 } else {
1585 m->obj_field_put(field_offset, v);
1586 }
1587 log_debug(aot, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
1588 }
1589
1590 // Done. Java code can see the archived sub-graphs referenced from k's
1591 // mirror after this point.
1592 if (log_is_enabled(Info, aot, heap)) {
1593 ResourceMark rm;
1594 log_info(aot, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s%s",
1595 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "",
1596 k->has_aot_initialized_mirror() ? " (aot-inited)" : "");
1597 }
1598 }
1599
1600 verify_the_heap(k, "after ");
1601 }
1602
1603 void HeapShared::clear_archived_roots_of(Klass* k) {
1604 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1605 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1606 if (record != nullptr) {
1607 Array<int>* entry_field_records = record->entry_field_records();
1608 if (entry_field_records != nullptr) {
1609 int efr_len = entry_field_records->length();
1610 assert(efr_len % 2 == 0, "sanity");
1611 for (int i = 0; i < efr_len; i += 2) {
1612 int root_index = entry_field_records->at(i+1);
1613 clear_root(root_index);
1614 }
1615 }
1616 }
1617 }
1618
1619 // Push all oop fields (or oop array elemenets in case of an objArray) in
1620 // _referencing_obj onto the _stack.
1621 class HeapShared::OopFieldPusher: public BasicOopIterateClosure {
1622 PendingOopStack* _stack;
1623 GrowableArray<oop> _found_oop_fields;
1624 int _level;
1625 bool _record_klasses_only;
1626 KlassSubGraphInfo* _subgraph_info;
1627 oop _referencing_obj;
1628 bool _is_java_lang_ref;
1629 public:
1630 OopFieldPusher(PendingOopStack* stack,
1631 int level,
1632 bool record_klasses_only,
1633 KlassSubGraphInfo* subgraph_info,
1634 oop orig) :
1635 _stack(stack),
1636 _found_oop_fields(),
1637 _level(level),
1638 _record_klasses_only(record_klasses_only),
1639 _subgraph_info(subgraph_info),
1640 _referencing_obj(orig) {
1641 _is_java_lang_ref = AOTReferenceObjSupport::check_if_ref_obj(orig);
1642 }
1643 void do_oop(narrowOop *p) { OopFieldPusher::do_oop_work(p); }
1644 void do_oop( oop *p) { OopFieldPusher::do_oop_work(p); }
1645
1646 ~OopFieldPusher() {
1647 while (_found_oop_fields.length() > 0) {
1648 // This produces the exact same traversal order as the previous version
1649 // of OopFieldPusher that recurses on the C stack -- a depth-first search,
1650 // walking the oop fields in _referencing_obj by ascending field offsets.
1651 oop obj = _found_oop_fields.pop();
1652 _stack->push(PendingOop(obj, _referencing_obj, _level + 1));
1653 }
1654 }
1655
1656 protected:
1657 template <class T> void do_oop_work(T *p) {
1658 int field_offset = pointer_delta_as_int((char*)p, cast_from_oop<char*>(_referencing_obj));
1659 oop obj = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_load_at(_referencing_obj, field_offset);
1660 if (!CompressedOops::is_null(obj)) {
1661 if (_is_java_lang_ref && AOTReferenceObjSupport::skip_field(field_offset)) {
1662 // Do not follow these fields. They will be cleared to null.
1663 return;
1664 }
1665
1666 if (!_record_klasses_only && log_is_enabled(Debug, aot, heap)) {
1667 ResourceMark rm;
1668 log_debug(aot, heap)("(%d) %s[%d] ==> " PTR_FORMAT " size %zu %s", _level,
1669 _referencing_obj->klass()->external_name(), field_offset,
1670 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1671 if (log_is_enabled(Trace, aot, heap)) {
1672 LogTarget(Trace, aot, heap) log;
1673 LogStream out(log);
1674 obj->print_on(&out);
1675 }
1676 }
1677
1678 _found_oop_fields.push(obj);
1679 }
1680 }
1681
1682 public:
1683 oop referencing_obj() { return _referencing_obj; }
1684 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1685 };
1686
1687 // Checks if an oop has any non-null oop fields
1688 class PointsToOopsChecker : public BasicOopIterateClosure {
1689 bool _result;
1690
1691 template <class T> void check(T *p) {
1692 _result |= (HeapAccess<>::oop_load(p) != nullptr);
1693 }
1694
1695 public:
1696 PointsToOopsChecker() : _result(false) {}
1697 void do_oop(narrowOop *p) { check(p); }
1698 void do_oop( oop *p) { check(p); }
1699 bool result() { return _result; }
1700 };
1701
1702 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop obj, oop referrer) {
1703 PointsToOopsChecker points_to_oops_checker;
1704 obj->oop_iterate(&points_to_oops_checker);
1705 return CachedOopInfo(OopHandle(Universe::vm_global(), referrer), points_to_oops_checker.result());
1706 }
1707
1708 void HeapShared::init_box_classes(TRAPS) {
1709 if (ArchiveHeapLoader::is_in_use()) {
1710 vmClasses::Boolean_klass()->initialize(CHECK);
1711 vmClasses::Character_klass()->initialize(CHECK);
1712 vmClasses::Float_klass()->initialize(CHECK);
1713 vmClasses::Double_klass()->initialize(CHECK);
1714 vmClasses::Byte_klass()->initialize(CHECK);
1715 vmClasses::Short_klass()->initialize(CHECK);
1716 vmClasses::Integer_klass()->initialize(CHECK);
1717 vmClasses::Long_klass()->initialize(CHECK);
1718 vmClasses::Void_klass()->initialize(CHECK);
1719 }
1720 }
1721
1722 void HeapShared::exit_on_error() {
1723 if (_context != nullptr) {
1724 ResourceMark rm;
1725 LogStream ls(Log(cds, heap)::error());
1726 ls.print_cr("Context");
1727 for (int i = 0; i < _context->length(); i++) {
1728 const char* s = _context->at(i);
1729 ls.print_cr("- %s", s);
1730 }
1731 }
1732 debug_trace();
1733 AOTMetaspace::unrecoverable_writing_error();
1734 }
1735
1736 // (1) If orig_obj has not been archived yet, archive it.
1737 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
1738 // trace all objects that are reachable from it, and make sure these objects are archived.
1739 // (3) Record the klasses of all objects that are reachable from orig_obj (including those that
1740 // were already archived when this function is called)
1741 bool HeapShared::archive_reachable_objects_from(int level,
1742 KlassSubGraphInfo* subgraph_info,
1743 oop orig_obj) {
1744 assert(orig_obj != nullptr, "must be");
1745 PendingOopStack stack;
1746 stack.push(PendingOop(orig_obj, nullptr, level));
1747
1748 while (stack.length() > 0) {
1749 PendingOop po = stack.pop();
1750 _object_being_archived = po;
1751 bool status = walk_one_object(&stack, po.level(), subgraph_info, po.obj(), po.referrer());
1752 _object_being_archived = PendingOop();
1753
1754 if (!status) {
1755 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1756 // as the Java code will take care of initializing this field dynamically.
1757 assert(level == 1, "VM should have exited with unarchivable objects for _level > 1");
1758 return false;
1759 }
1760 }
1761
1762 return true;
1763 }
1764
1765 bool HeapShared::walk_one_object(PendingOopStack* stack, int level, KlassSubGraphInfo* subgraph_info,
1766 oop orig_obj, oop referrer) {
1767 assert(orig_obj != nullptr, "must be");
1768 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
1769 // This object has injected fields that cannot be supported easily, so we disallow them for now.
1770 // If you get an error here, you probably made a change in the JDK library that has added
1771 // these objects that are referenced (directly or indirectly) by static fields.
1772 ResourceMark rm;
1773 log_error(aot, heap)("Cannot archive object " PTR_FORMAT " of class %s", p2i(orig_obj), orig_obj->klass()->external_name());
1774 debug_trace();
1775 AOTMetaspace::unrecoverable_writing_error();
1776 }
1777
1778 if (log_is_enabled(Debug, aot, heap) && java_lang_Class::is_instance(orig_obj)) {
1779 ResourceMark rm;
1780 LogTarget(Debug, aot, heap) log;
1781 LogStream out(log);
1782 out.print("Found java mirror " PTR_FORMAT " ", p2i(orig_obj));
1783 Klass* k = java_lang_Class::as_Klass(orig_obj);
1784 if (k != nullptr) {
1785 out.print("%s", k->external_name());
1786 } else {
1787 out.print("primitive");
1788 }
1789 out.print_cr("; scratch mirror = " PTR_FORMAT,
1790 p2i(scratch_java_mirror(orig_obj)));
1791 }
1792
1793 if (java_lang_Class::is_instance(orig_obj)) {
1794 Klass* k = java_lang_Class::as_Klass(orig_obj);
1795 if (RegeneratedClasses::has_been_regenerated(k)) {
1796 orig_obj = RegeneratedClasses::get_regenerated_object(k)->java_mirror();
1797 }
1798 }
1799
1800 if (CDSConfig::is_initing_classes_at_dump_time()) {
1801 if (java_lang_Class::is_instance(orig_obj)) {
1802 orig_obj = scratch_java_mirror(orig_obj);
1803 assert(orig_obj != nullptr, "must be archived");
1804 }
1805 } else if (java_lang_Class::is_instance(orig_obj) && subgraph_info != _dump_time_special_subgraph) {
1806 // Without CDSConfig::is_initing_classes_at_dump_time(), we only allow archived objects to
1807 // point to the mirrors of (1) j.l.Object, (2) primitive classes, and (3) box classes. These are initialized
1808 // very early by HeapShared::init_box_classes().
1809 if (orig_obj == vmClasses::Object_klass()->java_mirror()
1810 || java_lang_Class::is_primitive(orig_obj)
1811 || orig_obj == vmClasses::Boolean_klass()->java_mirror()
1812 || orig_obj == vmClasses::Character_klass()->java_mirror()
1813 || orig_obj == vmClasses::Float_klass()->java_mirror()
1814 || orig_obj == vmClasses::Double_klass()->java_mirror()
1815 || orig_obj == vmClasses::Byte_klass()->java_mirror()
1816 || orig_obj == vmClasses::Short_klass()->java_mirror()
1817 || orig_obj == vmClasses::Integer_klass()->java_mirror()
1818 || orig_obj == vmClasses::Long_klass()->java_mirror()
1819 || orig_obj == vmClasses::Void_klass()->java_mirror()) {
1820 orig_obj = scratch_java_mirror(orig_obj);
1821 assert(orig_obj != nullptr, "must be archived");
1822 } else {
1823 // If you get an error here, you probably made a change in the JDK library that has added a Class
1824 // object that is referenced (directly or indirectly) by an ArchivableStaticFieldInfo
1825 // defined at the top of this file.
1826 log_error(aot, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
1827 debug_trace();
1828 AOTMetaspace::unrecoverable_writing_error();
1829 }
1830 }
1831
1832 if (has_been_seen_during_subgraph_recording(orig_obj)) {
1833 // orig_obj has already been archived and traced. Nothing more to do.
1834 return true;
1835 } else {
1836 set_has_been_seen_during_subgraph_recording(orig_obj);
1837 }
1838
1839 bool already_archived = has_been_archived(orig_obj);
1840 bool record_klasses_only = already_archived;
1841 if (!already_archived) {
1842 ++_num_new_archived_objs;
1843 if (!archive_object(orig_obj, referrer, subgraph_info)) {
1844 // Skip archiving the sub-graph referenced from the current entry field.
1845 ResourceMark rm;
1846 log_error(aot, heap)(
1847 "Cannot archive the sub-graph referenced from %s object ("
1848 PTR_FORMAT ") size %zu, skipped.",
1849 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
1850 if (level == 1) {
1851 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1852 // as the Java code will take care of initializing this field dynamically.
1853 return false;
1854 } else {
1855 // We don't know how to handle an object that has been archived, but some of its reachable
1856 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
1857 // we have a real use case.
1858 AOTMetaspace::unrecoverable_writing_error();
1859 }
1860 }
1861 }
1862
1863 Klass *orig_k = orig_obj->klass();
1864 subgraph_info->add_subgraph_object_klass(orig_k);
1865
1866 {
1867 // Find all the oops that are referenced by orig_obj, push them onto the stack
1868 // so we can work on them next.
1869 ResourceMark rm;
1870 OopFieldPusher pusher(stack, level, record_klasses_only, subgraph_info, orig_obj);
1871 orig_obj->oop_iterate(&pusher);
1872 }
1873
1874 if (CDSConfig::is_initing_classes_at_dump_time()) {
1875 // The classes of all archived enum instances have been marked as aot-init,
1876 // so there's nothing else to be done in the production run.
1877 } else {
1878 // This is legacy support for enum classes before JEP 483 -- we cannot rerun
1879 // the enum's <clinit> in the production run, so special handling is needed.
1880 if (CDSEnumKlass::is_enum_obj(orig_obj)) {
1881 CDSEnumKlass::handle_enum_obj(level + 1, subgraph_info, orig_obj);
1882 }
1883 }
1884
1885 return true;
1886 }
1887
1888 //
1889 // Start from the given static field in a java mirror and archive the
1890 // complete sub-graph of java heap objects that are reached directly
1891 // or indirectly from the starting object by following references.
1892 // Sub-graph archiving restrictions (current):
1893 //
1894 // - All classes of objects in the archived sub-graph (including the
1895 // entry class) must be boot class only.
1896 // - No java.lang.Class instance (java mirror) can be included inside
1897 // an archived sub-graph. Mirror can only be the sub-graph entry object.
1898 //
1899 // The Java heap object sub-graph archiving process (see OopFieldPusher):
1900 //
1901 // 1) Java object sub-graph archiving starts from a given static field
1902 // within a Class instance (java mirror). If the static field is a
1903 // reference field and points to a non-null java object, proceed to
1904 // the next step.
1905 //
1906 // 2) Archives the referenced java object. If an archived copy of the
1907 // current object already exists, updates the pointer in the archived
1908 // copy of the referencing object to point to the current archived object.
1909 // Otherwise, proceed to the next step.
1910 //
1911 // 3) Follows all references within the current java object and recursively
1912 // archive the sub-graph of objects starting from each reference.
1913 //
1914 // 4) Updates the pointer in the archived copy of referencing object to
1915 // point to the current archived object.
1916 //
1917 // 5) The Klass of the current java object is added to the list of Klasses
1918 // for loading and initializing before any object in the archived graph can
1919 // be accessed at runtime.
1920 //
1921 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
1922 const char* klass_name,
1923 int field_offset,
1924 const char* field_name) {
1925 assert(CDSConfig::is_dumping_heap(), "dump time only");
1926 assert(k->defined_by_boot_loader(), "must be boot class");
1927
1928 oop m = k->java_mirror();
1929
1930 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
1931 oop f = m->obj_field(field_offset);
1932
1933 log_debug(aot, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
1934
1935 if (!CompressedOops::is_null(f)) {
1936 if (log_is_enabled(Trace, aot, heap)) {
1937 LogTarget(Trace, aot, heap) log;
1938 LogStream out(log);
1939 f->print_on(&out);
1940 }
1941
1942 bool success = archive_reachable_objects_from(1, subgraph_info, f);
1943 if (!success) {
1944 log_error(aot, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
1945 klass_name, field_name);
1946 } else {
1947 // Note: the field value is not preserved in the archived mirror.
1948 // Record the field as a new subGraph entry point. The recorded
1949 // information is restored from the archive at runtime.
1950 subgraph_info->add_subgraph_entry_field(field_offset, f);
1951 log_info(aot, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(f));
1952 }
1953 } else {
1954 // The field contains null, we still need to record the entry point,
1955 // so it can be restored at runtime.
1956 subgraph_info->add_subgraph_entry_field(field_offset, nullptr);
1957 }
1958 }
1959
1960 #ifndef PRODUCT
1961 class VerifySharedOopClosure: public BasicOopIterateClosure {
1962 public:
1963 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
1964 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
1965
1966 protected:
1967 template <class T> void do_oop_work(T *p) {
1968 oop obj = RawAccess<>::oop_load(p);
1969 if (!CompressedOops::is_null(obj)) {
1970 HeapShared::verify_reachable_objects_from(obj);
1971 }
1972 }
1973 };
1974
1975 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
1976 assert(CDSConfig::is_dumping_heap(), "dump time only");
1977 assert(k->defined_by_boot_loader(), "must be boot class");
1978
1979 oop m = k->java_mirror();
1980 oop f = m->obj_field(field_offset);
1981 if (!CompressedOops::is_null(f)) {
1982 verify_subgraph_from(f);
1983 }
1984 }
1985
1986 void HeapShared::verify_subgraph_from(oop orig_obj) {
1987 if (!has_been_archived(orig_obj)) {
1988 // It's OK for the root of a subgraph to be not archived. See comments in
1989 // archive_reachable_objects_from().
1990 return;
1991 }
1992
1993 // Verify that all objects reachable from orig_obj are archived.
1994 init_seen_objects_table();
1995 verify_reachable_objects_from(orig_obj);
1996 delete_seen_objects_table();
1997 }
1998
1999 void HeapShared::verify_reachable_objects_from(oop obj) {
2000 _num_total_verifications ++;
2001 if (java_lang_Class::is_instance(obj)) {
2002 Klass* k = java_lang_Class::as_Klass(obj);
2003 if (RegeneratedClasses::has_been_regenerated(k)) {
2004 k = RegeneratedClasses::get_regenerated_object(k);
2005 obj = k->java_mirror();
2006 }
2007 obj = scratch_java_mirror(obj);
2008 assert(obj != nullptr, "must be");
2009 }
2010 if (!has_been_seen_during_subgraph_recording(obj)) {
2011 set_has_been_seen_during_subgraph_recording(obj);
2012 assert(has_been_archived(obj), "must be");
2013 VerifySharedOopClosure walker;
2014 obj->oop_iterate(&walker);
2015 }
2016 }
2017 #endif
2018
2019 void HeapShared::check_special_subgraph_classes() {
2020 if (CDSConfig::is_initing_classes_at_dump_time()) {
2021 // We can have aot-initialized classes (such as Enums) that can reference objects
2022 // of arbitrary types. Currently, we trust the JEP 483 implementation to only
2023 // aot-initialize classes that are "safe".
2024 //
2025 // TODO: we need an automatic tool that checks the safety of aot-initialized
2026 // classes (when we extend the set of aot-initialized classes beyond JEP 483)
2027 return;
2028 } else {
2029 // In this case, the special subgraph should contain a few specific types
2030 GrowableArray<Klass*>* klasses = _dump_time_special_subgraph->subgraph_object_klasses();
2031 int num = klasses->length();
2032 for (int i = 0; i < num; i++) {
2033 Klass* subgraph_k = klasses->at(i);
2034 Symbol* name = subgraph_k->name();
2035 if (subgraph_k->is_instance_klass() &&
2036 name != vmSymbols::java_lang_Class() &&
2037 name != vmSymbols::java_lang_String() &&
2038 name != vmSymbols::java_lang_ArithmeticException() &&
2039 name != vmSymbols::java_lang_ArrayIndexOutOfBoundsException() &&
2040 name != vmSymbols::java_lang_ArrayStoreException() &&
2041 name != vmSymbols::java_lang_ClassCastException() &&
2042 name != vmSymbols::java_lang_InternalError() &&
2043 name != vmSymbols::java_lang_NullPointerException()) {
2044 ResourceMark rm;
2045 fatal("special subgraph cannot have objects of type %s", subgraph_k->external_name());
2046 }
2047 }
2048 }
2049 }
2050
2051 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = nullptr;
2052 HeapShared::PendingOop HeapShared::_object_being_archived;
2053 int HeapShared::_num_new_walked_objs;
2054 int HeapShared::_num_new_archived_objs;
2055 int HeapShared::_num_old_recorded_klasses;
2056
2057 int HeapShared::_num_total_subgraph_recordings = 0;
2058 int HeapShared::_num_total_walked_objs = 0;
2059 int HeapShared::_num_total_archived_objs = 0;
2060 int HeapShared::_num_total_recorded_klasses = 0;
2061 int HeapShared::_num_total_verifications = 0;
2062
2063 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
2064 return _seen_objects_table->get(obj) != nullptr;
2065 }
2066
2067 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
2068 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
2069 _seen_objects_table->put_when_absent(obj, true);
2070 _seen_objects_table->maybe_grow();
2071 ++ _num_new_walked_objs;
2072 }
2073
2074 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
2075 log_info(aot, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
2076 init_subgraph_info(k, is_full_module_graph);
2077 init_seen_objects_table();
2078 _num_new_walked_objs = 0;
2079 _num_new_archived_objs = 0;
2080 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
2081 }
2082
2083 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
2084 int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
2085 _num_old_recorded_klasses;
2086 log_info(aot, heap)("Done recording subgraph(s) for archived fields in %s: "
2087 "walked %d objs, archived %d new objs, recorded %d classes",
2088 class_name, _num_new_walked_objs, _num_new_archived_objs,
2089 num_new_recorded_klasses);
2090
2091 delete_seen_objects_table();
2092
2093 _num_total_subgraph_recordings ++;
2094 _num_total_walked_objs += _num_new_walked_objs;
2095 _num_total_archived_objs += _num_new_archived_objs;
2096 _num_total_recorded_klasses += num_new_recorded_klasses;
2097 }
2098
2099 class ArchivableStaticFieldFinder: public FieldClosure {
2100 InstanceKlass* _ik;
2101 Symbol* _field_name;
2102 bool _found;
2103 int _offset;
2104 public:
2105 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
2106 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
2107
2108 virtual void do_field(fieldDescriptor* fd) {
2109 if (fd->name() == _field_name) {
2110 assert(!_found, "fields can never be overloaded");
2111 if (is_reference_type(fd->field_type())) {
2112 _found = true;
2113 _offset = fd->offset();
2114 }
2115 }
2116 }
2117 bool found() { return _found; }
2118 int offset() { return _offset; }
2119 };
2120
2121 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
2122 TRAPS) {
2123 for (int i = 0; fields[i].valid(); i++) {
2124 ArchivableStaticFieldInfo* info = &fields[i];
2125 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
2126 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
2127 ResourceMark rm; // for stringStream::as_string() etc.
2128
2129 #ifndef PRODUCT
2130 bool is_test_class = (ArchiveHeapTestClass != nullptr) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0);
2131 const char* test_class_name = ArchiveHeapTestClass;
2132 #else
2133 bool is_test_class = false;
2134 const char* test_class_name = ""; // avoid C++ printf checks warnings.
2135 #endif
2136
2137 if (is_test_class) {
2138 log_warning(aot)("Loading ArchiveHeapTestClass %s ...", test_class_name);
2139 }
2140
2141 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD);
2142 if (HAS_PENDING_EXCEPTION) {
2143 CLEAR_PENDING_EXCEPTION;
2144 stringStream st;
2145 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name);
2146 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2147 }
2148
2149 if (!k->is_instance_klass()) {
2150 stringStream st;
2151 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name);
2152 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2153 }
2154
2155 InstanceKlass* ik = InstanceKlass::cast(k);
2156 assert(InstanceKlass::cast(ik)->defined_by_boot_loader(),
2157 "Only support boot classes");
2158
2159 if (is_test_class) {
2160 if (ik->module()->is_named()) {
2161 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary
2162 // core-lib classes. You need to at least append to the bootclasspath.
2163 stringStream st;
2164 st.print("ArchiveHeapTestClass %s is not in unnamed module", test_class_name);
2165 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2166 }
2167
2168 if (ik->package() != nullptr) {
2169 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy.
2170 stringStream st;
2171 st.print("ArchiveHeapTestClass %s is not in unnamed package", test_class_name);
2172 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2173 }
2174 } else {
2175 if (ik->module()->name() != vmSymbols::java_base()) {
2176 // We don't want to deal with cases when a module is unavailable at runtime.
2177 // FUTURE -- load from archived heap only when module graph has not changed
2178 // between dump and runtime.
2179 stringStream st;
2180 st.print("%s is not in java.base module", info->klass_name);
2181 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2182 }
2183 }
2184
2185 if (is_test_class) {
2186 log_warning(aot)("Initializing ArchiveHeapTestClass %s ...", test_class_name);
2187 }
2188 ik->initialize(CHECK);
2189
2190 ArchivableStaticFieldFinder finder(ik, field_name);
2191 ik->do_local_static_fields(&finder);
2192 if (!finder.found()) {
2193 stringStream st;
2194 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name);
2195 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2196 }
2197
2198 info->klass = ik;
2199 info->offset = finder.offset();
2200 }
2201 }
2202
2203 void HeapShared::init_subgraph_entry_fields(TRAPS) {
2204 assert(CDSConfig::is_dumping_heap(), "must be");
2205 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable();
2206 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK);
2207 if (CDSConfig::is_dumping_full_module_graph()) {
2208 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK);
2209 }
2210 }
2211
2212 #ifndef PRODUCT
2213 void HeapShared::setup_test_class(const char* test_class_name) {
2214 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields;
2215 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
2216 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below");
2217 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list");
2218
2219 if (test_class_name != nullptr) {
2220 p[num_slots - 2].klass_name = test_class_name;
2221 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME;
2222 }
2223 }
2224
2225 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass
2226 // during runtime. This may be called before the module system is initialized so
2227 // we cannot rely on InstanceKlass::module(), etc.
2228 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) {
2229 if (_test_class != nullptr) {
2230 if (ik == _test_class) {
2231 return true;
2232 }
2233 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses();
2234 if (klasses == nullptr) {
2235 return false;
2236 }
2237
2238 for (int i = 0; i < klasses->length(); i++) {
2239 Klass* k = klasses->at(i);
2240 if (k == ik) {
2241 Symbol* name;
2242 if (k->is_instance_klass()) {
2243 name = InstanceKlass::cast(k)->name();
2244 } else if (k->is_objArray_klass()) {
2245 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass();
2246 if (!bk->is_instance_klass()) {
2247 return false;
2248 }
2249 name = bk->name();
2250 } else {
2251 return false;
2252 }
2253
2254 // See KlassSubGraphInfo::check_allowed_klass() - we only allow test classes
2255 // to be:
2256 // (A) java.base classes (which must not be in the unnamed module)
2257 // (B) test classes which must be in the unnamed package of the unnamed module.
2258 // So if we see a '/' character in the class name, it must be in (A);
2259 // otherwise it must be in (B).
2260 if (name->index_of_at(0, "/", 1) >= 0) {
2261 return false; // (A)
2262 }
2263
2264 return true; // (B)
2265 }
2266 }
2267 }
2268
2269 return false;
2270 }
2271
2272 void HeapShared::initialize_test_class_from_archive(JavaThread* current) {
2273 Klass* k = _test_class;
2274 if (k != nullptr && ArchiveHeapLoader::is_in_use()) {
2275 JavaThread* THREAD = current;
2276 ExceptionMark em(THREAD);
2277 const ArchivedKlassSubGraphInfoRecord* record =
2278 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
2279
2280 // The _test_class is in the unnamed module, so it can't call CDS.initializeFromArchive()
2281 // from its <clinit> method. So we set up its "archivedObjects" field first, before
2282 // calling its <clinit>. This is not strictly clean, but it's a convenient way to write unit
2283 // test cases (see test/hotspot/jtreg/runtime/cds/appcds/cacheObject/ArchiveHeapTestClass.java).
2284 if (record != nullptr) {
2285 init_archived_fields_for(k, record);
2286 }
2287 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
2288 }
2289 }
2290 #endif
2291
2292 void HeapShared::init_for_dumping(TRAPS) {
2293 if (CDSConfig::is_dumping_heap()) {
2294 setup_test_class(ArchiveHeapTestClass);
2295 _dumped_interned_strings = new (mtClass)DumpedInternedStrings(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE);
2296 init_subgraph_entry_fields(CHECK);
2297 }
2298 }
2299
2300 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
2301 bool is_full_module_graph) {
2302 _num_total_subgraph_recordings = 0;
2303 _num_total_walked_objs = 0;
2304 _num_total_archived_objs = 0;
2305 _num_total_recorded_klasses = 0;
2306 _num_total_verifications = 0;
2307
2308 // For each class X that has one or more archived fields:
2309 // [1] Dump the subgraph of each archived field
2310 // [2] Create a list of all the class of the objects that can be reached
2311 // by any of these static fields.
2312 // At runtime, these classes are initialized before X's archived fields
2313 // are restored by HeapShared::initialize_from_archived_subgraph().
2314 for (int i = 0; fields[i].valid(); ) {
2315 ArchivableStaticFieldInfo* info = &fields[i];
2316 const char* klass_name = info->klass_name;
2317 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
2318
2319 ContextMark cm(klass_name);
2320 // If you have specified consecutive fields of the same klass in
2321 // fields[], these will be archived in the same
2322 // {start_recording_subgraph ... done_recording_subgraph} pass to
2323 // save time.
2324 for (; fields[i].valid(); i++) {
2325 ArchivableStaticFieldInfo* f = &fields[i];
2326 if (f->klass_name != klass_name) {
2327 break;
2328 }
2329
2330 ContextMark cm(f->field_name);
2331 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
2332 f->offset, f->field_name);
2333 }
2334 done_recording_subgraph(info->klass, klass_name);
2335 }
2336
2337 log_info(aot, heap)("Archived subgraph records = %d",
2338 _num_total_subgraph_recordings);
2339 log_info(aot, heap)(" Walked %d objects", _num_total_walked_objs);
2340 log_info(aot, heap)(" Archived %d objects", _num_total_archived_objs);
2341 log_info(aot, heap)(" Recorded %d klasses", _num_total_recorded_klasses);
2342
2343 #ifndef PRODUCT
2344 for (int i = 0; fields[i].valid(); i++) {
2345 ArchivableStaticFieldInfo* f = &fields[i];
2346 verify_subgraph_from_static_field(f->klass, f->offset);
2347 }
2348 log_info(aot, heap)(" Verified %d references", _num_total_verifications);
2349 #endif
2350 }
2351
2352 // Keep track of the contents of the archived interned string table. This table
2353 // is used only by CDSHeapVerifier.
2354 void HeapShared::add_to_dumped_interned_strings(oop string) {
2355 assert_at_safepoint(); // DumpedInternedStrings uses raw oops
2356 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(string), "must be");
2357 bool created;
2358 _dumped_interned_strings->put_if_absent(string, true, &created);
2359 if (created) {
2360 // Prevent string deduplication from changing the value field to
2361 // something not in the archive.
2362 java_lang_String::set_deduplication_forbidden(string);
2363 _dumped_interned_strings->maybe_grow();
2364 }
2365 }
2366
2367 bool HeapShared::is_dumped_interned_string(oop o) {
2368 return _dumped_interned_strings->get(o) != nullptr;
2369 }
2370
2371 // These tables should be used only within the CDS safepoint, so
2372 // delete them before we exit the safepoint. Otherwise the table will
2373 // contain bad oops after a GC.
2374 void HeapShared::delete_tables_with_raw_oops() {
2375 assert(_seen_objects_table == nullptr, "should have been deleted");
2376
2377 delete _dumped_interned_strings;
2378 _dumped_interned_strings = nullptr;
2379
2380 ArchiveHeapWriter::delete_tables_with_raw_oops();
2381 }
2382
2383 void HeapShared::debug_trace() {
2384 ResourceMark rm;
2385 oop referrer = _object_being_archived.referrer();
2386 if (referrer != nullptr) {
2387 LogStream ls(Log(aot, heap)::error());
2388 ls.print_cr("Reference trace");
2389 CDSHeapVerifier::trace_to_root(&ls, referrer);
2390 }
2391 }
2392
2393 #ifndef PRODUCT
2394 // At dump-time, find the location of all the non-null oop pointers in an archived heap
2395 // region. This way we can quickly relocate all the pointers without using
2396 // BasicOopIterateClosure at runtime.
2397 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
2398 void* _start;
2399 BitMap *_oopmap;
2400 int _num_total_oops;
2401 int _num_null_oops;
2402 public:
2403 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
2404 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
2405
2406 virtual void do_oop(narrowOop* p) {
2407 assert(UseCompressedOops, "sanity");
2408 _num_total_oops ++;
2409 narrowOop v = *p;
2410 if (!CompressedOops::is_null(v)) {
2411 size_t idx = p - (narrowOop*)_start;
2412 _oopmap->set_bit(idx);
2413 } else {
2414 _num_null_oops ++;
2415 }
2416 }
2417 virtual void do_oop(oop* p) {
2418 assert(!UseCompressedOops, "sanity");
2419 _num_total_oops ++;
2420 if ((*p) != nullptr) {
2421 size_t idx = p - (oop*)_start;
2422 _oopmap->set_bit(idx);
2423 } else {
2424 _num_null_oops ++;
2425 }
2426 }
2427 int num_total_oops() const { return _num_total_oops; }
2428 int num_null_oops() const { return _num_null_oops; }
2429 };
2430 #endif
2431
2432 void HeapShared::count_allocation(size_t size) {
2433 _total_obj_count ++;
2434 _total_obj_size += size;
2435 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2436 if (size <= (size_t(1) << i)) {
2437 _alloc_count[i] ++;
2438 _alloc_size[i] += size;
2439 return;
2440 }
2441 }
2442 }
2443
2444 static double avg_size(size_t size, size_t count) {
2445 double avg = 0;
2446 if (count > 0) {
2447 avg = double(size * HeapWordSize) / double(count);
2448 }
2449 return avg;
2450 }
2451
2452 void HeapShared::print_stats() {
2453 size_t huge_count = _total_obj_count;
2454 size_t huge_size = _total_obj_size;
2455
2456 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2457 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize;
2458 size_t count = _alloc_count[i];
2459 size_t size = _alloc_size[i];
2460 log_info(aot, heap)("%8zu objects are <= %-6zu"
2461 " bytes (total %8zu bytes, avg %8.1f bytes)",
2462 count, byte_size_limit, size * HeapWordSize, avg_size(size, count));
2463 huge_count -= count;
2464 huge_size -= size;
2465 }
2466
2467 log_info(aot, heap)("%8zu huge objects (total %8zu bytes"
2468 ", avg %8.1f bytes)",
2469 huge_count, huge_size * HeapWordSize,
2470 avg_size(huge_size, huge_count));
2471 log_info(aot, heap)("%8zu total objects (total %8zu bytes"
2472 ", avg %8.1f bytes)",
2473 _total_obj_count, _total_obj_size * HeapWordSize,
2474 avg_size(_total_obj_size, _total_obj_count));
2475 }
2476
2477 bool HeapShared::is_archived_boot_layer_available(JavaThread* current) {
2478 TempNewSymbol klass_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_CLASS);
2479 InstanceKlass* k = SystemDictionary::find_instance_klass(current, klass_name, Handle());
2480 if (k == nullptr) {
2481 return false;
2482 } else {
2483 TempNewSymbol field_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_FIELD);
2484 TempNewSymbol field_signature = SymbolTable::new_symbol("Ljdk/internal/module/ArchivedBootLayer;");
2485 fieldDescriptor fd;
2486 if (k->find_field(field_name, field_signature, true, &fd) != nullptr) {
2487 oop m = k->java_mirror();
2488 oop f = m->obj_field(fd.offset());
2489 if (CompressedOops::is_null(f)) {
2490 return false;
2491 }
2492 } else {
2493 return false;
2494 }
2495 }
2496 return true;
2497 }
2498
2499 #endif // INCLUDE_CDS_JAVA_HEAP